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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - clang hangs in llvm::JumpThreadingPass::ComputeValueKnownInPredecessors on a tiny input"
href="https://bugs.llvm.org/show_bug.cgi?id=33880">33880</a>
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<th>Summary</th>
<td>clang hangs in llvm::JumpThreadingPass::ComputeValueKnownInPredecessors on a tiny input
</td>
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<th>Product</th>
<td>new-bugs
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>new bugs
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>kcc@google.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org, max.kazantsev@azul.com
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</tr></table>
<p>
<div>
<pre>found with clang-proto-fuzzer on r308641.
clang -cc1 -triple x86_64-unknown-linux-gnu -O2 -emit-obj slow5.c
All time is spent in a recursive call to
llvm::JumpThreadingPass::ComputeValueKnownInPredecessors
void foo(int *a) {
while ((1 + 1)) {
while ((a[96] * a[96])) {
a[0] = (1024);
while (a[0]) {
while (a[0]) {
(void)0;
while ((a[96] * ((a[96] * a[96]) < 1))) {
a[96] = (1 + 1);
}
a[0] = (a[0] + a[0]);
}
}
}
}
}
(Not sure if this is related to <a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED - 3+ minutes is spent in ScalarEvolution on a tiny test"
href="show_bug.cgi?id=33753">https://bugs.llvm.org/show_bug.cgi?id=33753</a> or
<a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED - SelectionDAGISel::CodeGenAndEmitDAG takes 3 minutes to compile 11 lines of C++,"
href="show_bug.cgi?id=33494">https://bugs.llvm.org/show_bug.cgi?id=33494</a></pre>
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